Mikuru Katsuhara, known as Micchon to close friends, is a core Eden of the East member and a highly skilled programmer. She crafted the group's essential image recognition software, which identifies people and objects in photos by cross-referencing social networks and online data. Mikuru also repairs computer hardware.

Typically reserved, she often presents an air of resting disinterest or emotionlessness, appearing disengaged. This masks a tendency to become easily flustered, especially in stressful or unfamiliar situations. Shy around strangers, she hesitates in new social interactions, only showing openness and comfort with trusted companions like her close friend Saki Morimi.

Her laptop is her most prized possession, meticulously maintained and jealously guarded; she strictly controls its use and strongly resists others handling or accessing it. Within Eden, she collaborates closely with Kazuomi Hirasawa, Satoshi Ōsugi, Haruo Kasuga, Sis, and Yutaka Itazu. Her technical expertise proves vital during critical events, enabling access to the Seleção database and aiding the search for Akira Takizawa.

When Eden evolves into a formal venture after the missile interceptions, Mikuru remains involved. She continues contributing her programming skills to the group's operations and missions, including tracking activities and system analyses during the search for Takizawa in New York and confrontations with other Seleção members. Her role remains consistently technical and supportive throughout.